Service Manual

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DIAGNOSTIC ERROR CODES AND TROUBLESHOOTING PROCEDURES FOR EF MODELS
WITH ICON SYSTEMS CONTROL
Error Code
Definition
of Code
Cause of Problem and Actions Taken to Correct
No code – blank
display
No power to
the unit or
switch is
off.
• Check power supply to the water heater.
• Make sure water heater is plugged in and the breaker is on.
• Check if there is 120 volts power supply to the LINE connections on the
control board.
• Verify 24 volts at display.
• Check for loose wires, defective transformer.
• Check wire harness connections from display to the control board.
9,22
Low flame
sense
signal
• Check microamp output of flame sense
• Inspect flame sensor and wire
• Inspect burner for debris
49
Voltage too
low or high
• Measure the incoming line voltage.
• Voltage should be 115-125 volts.
• If the voltage is not within this range or there is drastic fluctuation, then
have the incoming power supply checked.
• If the line voltage is satisfactory, check the output from the transformer to
make sure it is 22-26 volts.
• Replace transformer or wiring if defective.
53
AC Inputs
phase
reversed
• Check the module and display connections.
• Check the module power supply and make sure that frequency, voltage
and VA capacity of the transformer meet specifications.
• Check to make sure the wiring connections on the control module from
terminals J4-10 and J8-2 are connected together.
62
Fan speed
not proved
• Check the pulse width modulation (PWM) wire harness connection from
the blower to the control module.
• Make sure the pin terminals make solid contact.
• Measure the resistance of each wire in the wire harness from the terminal
ends.
• Replace wire harness if defective.
• If value remains out of range, this hold will change to lockout 123 (defined
below)
67
Normally
closed vent
safety
circuit
opened
• Check wiring to the normally closed blocked vent pressure switch and
vent limit switch.
• Use a voltmeter to find out if either the pressure switch or the high limit
switch has opened.
• If so, determine the cause (blocked vent terminal, clogged condensate
drain, high temperature in compartment).
• If limit switches are closed, check wiring for shorts.
• Measure continuity.
• If limit switches and wiring check O.K., replace control module.
NOTICE
The ICON control system can produce soft and hard lockouts. Soft lockouts are displayed if active
and are not stored in Diagnostic Mode history. The control will periodically attempt to resume
normal operation when in soft lockout conditions. If the system resumes normal operation a soft
lockout will clear instantly; hard lockouts will display if active and require manual reset. Up to ten
previous Hard lockouts are logged chronologically (newest first) in Diagnostic Mode history.
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